It is well known that glass is extensively used in the electronics industry as an insulator because of its dielectric constant and other good qualities. The art of glass making and the production of various parts from glass emanates from ancient times. Such techniques pre-form glass into a desired final shape or product from the liquid state, as by molding techniques and so on. There are literally hundreds of various recipes for making glass depending upon the use, nature and purpose to which the glass is used.
While glass can be machined, polished and mechanically operated on, great care has to be taken in such processes to avoid fracture or rupturing of the glass part. The problem becomes further complicated when fabricating or operating on thin, small cross-sectional glass parts.
Such glass parts as used in the electronics field may be ultra-miniature washers for electrical insulation, glass-backing plates for electrical circuits and so on. Due to the advent of integrated circuits and the general complexity of producing complicated electronic assemblies in very small packages, the desire to fabricate ultra-small glass parts is paramount. For example, in the field of transducers, which are devices for measuring pressure or force in an external environment, it is desirable to fabricate a semiconductor transducing assembly on a small glass surface to insulate the strain sensing elements from the environment. Due to the ultra-miniature size of such transducers, as piezoresistive strain gages, the glass-backing has to be both thin and small to permit the necessary insulation without losing the advantages of miniaturization.
The resultant transducer structure embodies one or more piezoresistive transducer elements mounted and securely affixed to a thin glass diaphragm (3 mils or less). The dimensions of such a piezoresistor may be in the order of 0.0002 inches thick and 0.0002 inches wide.
The glass-backed transducer can then be secured to another diaphragm as a metal or semiconductor structure or may be thusly utilized.
It is therefore an object of the present invention to provide a method of fabricating small glass parts without fear of fracture or rupturing the same.
It is a further object to provide a miniature semiconductor transducer mounted on a thin, glass-backed plate.